As the germ line is the source of totipotant stem cells in most organisms, studies of how germ cells maintain totipotency are a wonderful model for understanding the maintenance of stem cell totipotency in general. Up until this point most studies of stem cell populations have focused on genes that must be expressed in stem cells to maintain their identity. However recently the germ lineage in many organisms has been shown to be transcriptionally quiescent, suggesting that the totipotency of these cells is largely maintained through repressive mechanisms. Therefore, understanding repressive mechanisms in the germ lineage is essential to understanding the mechanisms guarding stem cell identity. The gene Nanos is a translational represser and has a role in maintaining the germ lineage from fly to human. The goal of this research is to understand the repressive mechanisms that are involved in stem cell maintenance by studying how the regulator Nanos maintains the germ line. Nanos function will be studied in C. elegans by ectopically expressing Nanos to determine which germ line characteristics it controls. In addition, both forward and reverse genetic approaches will be used to identify targets of Nanos translational repression.